As a semiconductor device containing a solid-state image sensing device, there is a back illumination complementary metal oxide semiconductor (CMOS) image sensor. In the back illumination CMOS image sensor, light enters from a back side of a substrate on which an electrode layer, a wiring layer, etc. are not disposed, the light is converted into an electric signal by a photo-diode, the electric signal is outputted to the outside of the substrate.
In the case of outputting the electric signal to the back side of the substrate, an electrode is provided on the back side of the substrate and is connected to a metal wiring layer through a via which penetrates the substrate.
Therefore, after the support substrate is bonded to the front side of the substrate on which the metal wiring layer is formed so that the substrate is reinforced, the substrate is ground from the back side so as to thin the substrate, and a via-hole is made by dry etching from the back side of the substrate. The dry etching is generally performed using a gas of fluorine system.
Accordingly, when the via-hole extends to the metal wiring layer during the dry etching, it is a problem that the metal wiring layer to which the via-hole extends is corroded by the gas of fluorine system.